Greeting Card CompaniesGreeting Card Companies often have opportunities for individuals to write,  illustrate and submit photos on a freelance basis.  Submission procedures vary among publishers.  Take the time to check out each company and have an idea of what is unique about their products before you submit.

Here is a great resource to get you started.  I highly recommend it: How to Write and Sell Greeting Cards, Bumper Stickers, T-Shirts and Other Fun Stuff

Below you will find several Greeting Card and Gift Companies who do take submissions:

American Greetings

Avanti Press Inc.

Blue Mountain Arts 

Calypso Cards 

Comstock Marketplace

Freedom Greeting Cards

Gallant Greetings

Global Graphics & Gifts

Graphique de France

Hallmark

123 GreetingsRaise.com

Marian Heath 

Moonlighting Cards

Nobleworks Cards

Oatmeal Studios

Peaceable Kingdom 

P.S. Greetings 

Zazzle 

Check out these great resources as well:

7 Mistakes Greeting Card Writers Make
Freelance Writing for Greeting Card Companies: 2nd Edition
The Greeting Card Business Manual: A Practical Handbook for the Self-Publishing Entrepreneur